The present invention refers to a diathermic fluid heat generator, also said pipe nest heating furnace, of the type described in the preamble of claim 1, by which it is possible to carry out a selective control of the thermal fluid circulation to detect the starting of possible cracking phenomena or unusual operating conditions.
In several fields, in particular in the production of synthetic fibres and yarns, it is required to dispose of large quantities of thermal energy at high temperature, maintaining low operating pressures of the plant for safety as well as for management economy reasons.
It is also known that some type of synthetic oils, more generally known as diathermic oils, used as heat transfer fluid, even at temperatures in the range of some hundreds of degrees, have a very low vapour pressure, typically of some bars, with respect to pressure values which are remarkably higher than the steam used as thermal fluid for heat transfer.